Randy Thomasson, president of Campaign for Children and Families, speaks out against the California State Supreme Court decision overturning a voter-approved ban on gay marriage during a news conference at the Capitol in Sacramento, Calif., on Thursday, May 15, 2008.

Religious beliefs and the Bible are the most often cited reasons for opposing gay marriage, according to a USA Today/Gallup poll. Those who favor gay marriage are most likely to mention equal rights or personal choice as the reasons for their position.

Among those who oppose same-sex marriage, Gallup asked an open-ended question -- "what are some of the reasons you oppose legal same-sex marriages?" Forty-seven percent of those respondents defended their position on the basis of religious beliefs or the Bible. Another 20 percent said marriage should be between a man and a woman and 16 percent said gay marriage is morally wrong or that they have traditional beliefs about marriage.

Only a few gay marriage opponents said their opposition was based upon the view that civil unions are sufficient (six percent), homosexuality is unnatural or against the laws of nature (five percent), or that gay marriage would undermine the traditional family structure (five percent).

Those who favor gay marriage most often said their support was based upon equal rights or that everyone should have the same rights or freedoms (32 percent), or based upon personal choice or that love or happiness, not sexual orientation, is what is important (32 percent). Another 14 percent said it was not their business or not the government's business to decide who can get married.

Some of the less common answers among gay marriage supporters were they have gay friends or family members (nine percent), everyone is equal in God's eyes (five percent), homosexuals are born that way (four percent), medical, insurance or financial reasons (three percent), and the need to separate church and state (two percent).

Overall, 53 percent supported gay marriage while 46 percent opposed, which matched the record high for same-sex marriage support in Gallup polling set in May 2011.

The greatest opposition to gay marriage came from those aged 65 and older (57 percent), Republicans (69 percent) and those who attend church weekly (70 percent). The greatest support for same-sex marriage came from 18- to 29-year-olds (73 percent), Democrats (73 percent), and those who attend church less often (70 percent).

This year, President Barack Obama announced that he changed his position on gay marriage. He had been opposed but now supports it. Additionally, proponents of government recognized same-sex marriages won ballot measure victories in four states -- Maine, Maryland, Minnesota and Washington.

The Nov. 26-29 poll of 1,015 adults has a margin of error of plus or minus four percentage points.